While DC's average book superhero star is indeed stronger than Marvel's (I am speaking of the popular ones), when you reach the cosmic level Marvel simply has too many powerful cosmic threats, and is seriously hampered by the very real possibility that the Presence isn't actually omnipotent.
I don't know, when you get to the highest levels, its all the same IMO, both have their ultimate omnipotent "God". TOAA and the Presence are basically the maximally powerful beings in each universe respectively. I don't know about the doubts you have about the Presence, but based on ALL feats and statements and the fact it is based on the Judeo-Christian God (especially in the Vertigo imprints), the evidence overwhelmingly supports that he is supreme.
Only here is the thing: He had an equal in the Great Evil Beast, and only became possibly omnipotent after absorbing it. HOWEVER, the existence of the Primal Monitor also casts his supremity in doubt, since the DC Multiverse created by the Presence is apparently a germ in comparison to it (Though the PM and the Presence may be synonymous, Final Crisis was weird). Marvel is also simply bigger, being a couple tiers larger than DC's verse.